[Theme: Oxygen] create 2 column layout template?

Hi, I’m working on top of the Oxygen theme and I want a two column template available for: left-side column and the remainder of the width for content. Rather than creating a new template I figured it would be best to edit the page-template-fullwidth.php file which I do not need.

I’ve spotted an IF function for this template (theme_embed_defaults – width) and changed it to the correct width for the content column, and also spotted and amended this:

if ( is_page_template( 'page-template-fullwidth.php' ) ) {
		$sidebars_widgets['primary'] = true;
		$sidebars_widgets['secondary'] = false;

I’ve tried all the obvious ways to get it to work but despite the menu showing up its got no content in it; the left-column does show as a rounded box inbetween the header and content.

So, why is my template showing an empty primary-sidebar please?
Test site: linen cupboard dot com slash shop
See account/checkout/contact pages.
Thanks …